Air collet closer



Filed Sept. 9, 1946 \NVENTO .CHARLEs KoomA M "0... ATTORN Ys which are performed.

Patented Dec. 7, 1948 The present inventionrelatestoapressure controlled closer for collets,in practiceoperated by pneumatic or air pressure for the releasable grip-i ping and holdingwork which is to be processed on a lathe or similar *iriachinel The feeding of 75 work to be processe n; wardly at meduter end rk,ithe workfb'eing gripped and held sou 'attneproeessingtb be done tnereoamay be accomplished, and after it is done a release for a successive feeding .of the work isdesirable in connection with machine lathes and other machines which may do '.1analogouspwork.

My invention is directed to a. verypractical; sturdy and economical structure which maybe associated with a lathe spindle and operatively connected therewith, which may be i rendered efiectivef to "grip the work by turning on the pressureor. release itby shutting such pressure off, being done in a very expeditiousmanner with saving of time and reduction of cost in the processing operations It is a primary objectand purpose of sent mventionto provide a useful and practic lc ollet closer. readily applied wane installed on a lathe, and one which is sure and certain in its operation.

An understanding of the invention may be had from the following description, taken. in connection with the accompanying drawing, in which Fig. 1 is a fragmentary longitudinal vertical section of a driven lathe spindle having my invention applied thereto, and

Fig. 2 shows in perspective and longitudinal section the major parts of the collet closure structure of my invention, the roller bearings utilized therewith not being shown.

Like reference characters refer to like parts in the different figures of the drawing.

The lathe spindle I is of conventional structure, and has a longitudinal passage therethrough. It is mounted for rotation in suitable bearings, illustrated diagrammatically at 2, which are spaced apart and between which a drive for the spindle may be located for turningit about its longitudinal axis. The front or outer end of the spindle is exteriorly threaded for the detachable connection of the outer member. 3 of a collet which is of well known structure, at its outer end having inwardly converging conicalsides.

The rear end of the rotating lathe spindle I is exteriorly threaded, and the sleeve 4 has an enlarged interiorly threaded end 5 connected therewith. It may be held in fixed relation to the spindle I by a set screw as shown. The interior member 6 of the collet has the usual frustoconical .2 Glaims. (01. 279 1 head fandfis 1 longitudinally divided or split at spaced distances around it] lt extends into the outei'member 3 of the collet and into'the hollow spindl 'l having connected thereto; preferably by screw connectiom'f an interior elongated sleeve or tube 1 whichfextends throughfthe spindle and the sleeve 4 connected therewith, and at its rear endisexteriorlythreaded; The rod 8 shown as passing through the sleeve or tube 1 and themterior cbllet member] 6; is f the work which is to be processed and may be fedthrough the one: when not gripped by the interior memberdbutis held said interior collet member "at thettimes that processing operationsfiare tob'e formed on it at its forwardly projecting phenomena With my inventiona cylinder-8 is provided wmenl between its ends; has an integraltrans- From the web asleeve bearing l'l extends reap wardly part of the way to but short of thedear "end of the cylinder 9. 1 A nietalcupmemberhaving a bottomdl and continuous cylindricalwalls I3 hasacentral' opening through which theforward enlarged interiorly threaded portion 5 1 of the sleeve 4 passes, said bottom l2 being. located against the forward side of the web I0.

In the rear open end of the cylinder 9 a similar cup member having a bottom I4 and a continuous annular wall I5 is inserted. It has a central opening for the free passage of the smaller diameter, rear end portion of the sleeve 4. A cap having a cylindrical wall l5 and an outer end I! is slidably received over said sleeve 4, and the outer end 11 has a central opening for the free passage of the exteriorly threaded end of the tube 1. A nut i8 is adjustably mounted on the rear end of the tube 1 and held in any position to which adjusted by a set screw.

Roller bearingslS have their outer retaining rings pressed into the cup members described, within the walls I 3 and 15, thereof with the inner retaining ring of the forward roller bearing around the head 5 of the sleeve 4, and the inner ring of the rear cup bearing around the inner end portion of the wall I6 of the cap described.

A flat ring 20 is located within the rear end portion of the cylinder 9, sleeve 4 passing there through at one side it is adapted to be pressed against the inner side of the bottom M of the rear cup member. A piston of annular form, including a metal ring 2| seated within an annular valve 22 of suitable material and firmly secured thereto is located against the inner side of the ring 20. The member 22 of the piston is of channel form in cross section, the ring 2| being permanently connected to its web and the flanges of the valve member 22 are located with the outer flange against the inner side of the cylinder 9, and the inner flange against the sleeve l I. This provides a closed annular chamber 23 for the reception of pressure which is supplied to the chamber through a pipe or conduit 24 connected with the cylinder 9 and leading to the chamber, through which, in practica compressed air is supplied.

When the (member at 23 is supplied with air under pressure, the piston is forced to the right (Fig. 1) pressing the ring 20 against the adjacent cup member and transmitting such pressure through the inner ring retainer of the roller bear-;.;-

ing [9 to the wall [6 of the cap and therefrom to the nut I8. The piston ring 'II, the rearare member and the rear roller bearing, cap l land nut I8 are thereupon moved to the right; and

4 tured and is certain and efiective in its working. The invention is defined in the appended claims and is to be considered comprehensive of all forms of structure coming within their scope.

I claim: 1. The combination with a rotatably mounted spindle having a chuck at one end and a tube extending through the spindle and projecting from the end opposite the chuck, said tube being enimcte gto said chuek to operate the same by longitudinal movement, of a sleeve connected to the spindle and rotatable therewith, a stationary cylinder having an in-turned flange between its ends surrounding said sleeve, a piston within the cylinder, a cup slidably mounted at the end of the sleevefmeahs for connecting the cup to said tube, anti-frictionbearing means between the cup the tube 1 and the inner collet member $1 :are

moved longitudinally inthe same direction. This causes the jaws or the inner collet' member 5 to be moved by a wedging action toward each other and against the rod *8, gripping it seeurely and holding it until the pressure in the;chan 1ber ,-23 is released, Then thus gripped and h d; the inner col-let member turns with the outer memher 3 and with the spindle l of the lathein its rotation. The cylinder 9, the piston structure and the two cup members are stationarythe roller bearings 18 permitting the rotation-oi the spindle and its connected sleeve and cap relative to the stationary cylinder 5 n On release of the pressure the innericol-let member 5 may be released and the rode-red torward a desired amount tor the next-processing operations. While the machine processing is occurring on the 'forward "endportion of; therod, the pressure within the chamber 23is maintamed, and the grippingand holding of the rodsl is continuous.

The structure described is .readilyimanuf actured and is very easily applied to the spindles of lathes or other similar machines, The structure of the invention is economically manufacand the piston'ant'i-friction bearing means between the sleeve and the cylinder, and means for injecting fluid under pressure between said inrdl an i i a t 2. The elements of; claim 1 combined with, a cylindrical portion formed on said in-turned flange and closelysurrounding said sleeve ravidi-ng-an annular space withinthe cylinder, said pistonbeing annular and located within said annular space, and said injecting means coinmunicating withsaid annular v r a n Kooma,

' "shimmers arn v j The following referenoQ of mm in the file ofthis-rpetent:

5;," currso'smrrsrarsms Number Name Date 2,279,730 Bradley if. .i .inprt [1942 2,415,181 John-sen;innnrnnrnebia 1047 Number Country H v 2 z 1,45s area-remainintole a t, i924 538,509 Germanyu n -icr chlwov 14,1931 

